a. Field of the Invention
The invention relates to a touch-sensitive display device.
b. Description of the Related Art
FIG. 11 shows an exploded diagram of a conventional touch-sensitive display device. Referring to FIG. 11, a touch-sensitive display device 100 includes a touch panel 102 and a display panel 104. During the assembly of the touch-sensitive display device 100, an enclosed sealant 106 is formed on the display panel 104 by screen printing, and the touch panel 102 is attached to the display panel 104 by the sealant 106.
Typically, when light travels from a medium with a higher refractive index to a medium with a lower refractive index and an angle of incidence is greater than the critical angle, an optical phenomenon of total reflection occurs. Referring to FIG. 12, when the touch panel 102 and the display panel 104 are combined with each other, an air gap 108 is formed between the touch panel 102 and the display panel 104 and surrounded by the sealant 106. In case a substrate of the touch panel 102 is a glass substrate, and ambient light that travels from the glass substrate (refractive index equal to about 1.5) to the air gap 108 (refractive index equal to about 1) has an angle of incidence larger than the critical angle, total reflection may occur. Under the circumstance, glare is shone on a surface of the touch panel 102 to cause visual discomfort. Besides, backlight that travels from a glass substrate to the air gap 108 and has an angle of incidence larger than the critical angle may be totally reflected to lower backlight utilization efficiency.